Control device of the spring type particularly for a high-voltage or medium-voltage circuit breaker or switch

Abstract

The control device possesses a rigid main part combining most of the functional elements of this type of control device. It is made up of two portions of a rotary shaft, having placed between them a cam and a support arm that are connected together by a pivot that is offset relative to the axis of rotation. A toothed wheel having an inner set of teeth is placed around the support arm that is provided with a rachet system. The toothed wheel has an outer set of teeth-driven by a motor, via an intermediate gearwheel. The pivot controls the compression of the actuator spring by the assembly rotating. The device is applicable to high and medium voltage circuit breakers and switches.

Claims

1. A spring type control device comprising: a spring for delivering energy in order to move a movable contact of a circuit breaker or a switch; a rotary shaft for transmitting energy needed for loading the spring; a toothed wheel receiving the energy delivered by the spring via an outer set of teeth and designed to drive the rotary shaft while loading the spring; a ratchet system for coupling and uncoupling the toothed wheel and the rotary shaft; a cam secured to the rotary shaft for transmitting the energy delivered by the spring to the movable contact of the circuit breaker or switch; a support arm secured to the rotary shaft and carrying the ratchet system and around which the toothed wheel is placed; and a pivot fastened to the support arm, being axially offset relative to the rotary shaft and mechanically connected to the spring; wherein the rotary shaft, the cam, the support arm, and the pivot constitute a single part in the form of a crankshaft, the pivot being placed centrally between the cam and the support arm, the pivot being connected to a first end of the spring by a connecting rod, the connecting rod having a first end pivotally connected on the pivot and having a second end connected to the first end of the spring, the rotary shaft being made up of two portions, one of the portions beside the cam and the other portion beside the support arm.

2. A spring type control device comprising: a spring for delivering energy in order to move a movable contact of a circuit breaker or a switch; a rotary shaft for transmitting energy needed for loading the spring; a toothed wheel receiving the energy delivered by the spring via an outer set of teeth and designed to drive the rotary shaft while loading the spring; a ratchet system for coupling and uncoupling the toothed wheel and the rotary shaft; a cam secured to the rotary shaft for transmitting the energy delivered by the spring to the movable contact of the circuit breaker or switch; a support arm secured to the rotary shaft and carrying the ratchet system and around which the toothed wheel is placed; and a pivot fastened to the support arm, being axially offset relative to the rotary shaft and mechanically connected to the spring, wherein the rotary shaft, the cam, the support arm, and the pivot constitute a single part in the form of a crankshaft, the pivot being placed centrally between the cam and the support arm, the pivot being connected to a first end of the spring by a connecting rod, the connecting rod having a first end pivotally connected on the pivot and having a second end connected to the first end of the spring, the rotary shaft being made up of two portions, one of the portions beside the cam and the other portion beside the support arm, and wherein the support arm possesses at least three angularly offset branches with peripheral surfaces supporting the toothed wheel by contacting the tips of teeth of an inner set of teeth, the ratchet system being placed on one of the branches to co-operate with the inner set of teeth of the toothed wheel.

3. A circuit breaker using a spring type system, comprising: a spring for delivering energy in order to move a movable contact of a circuit breaker or a switch; a rotary shaft for transmitting energy needed for loading the spring; a toothed wheel receiving the energy delivered by the spring via an outer set of teeth and designed to drive the rotary shaft while loading the spring; a ratchet system for coupling and uncoupling the toothed wheel and the rotary shaft; a cam secured to the rotary shaft for transmitting the energy delivered by the spring to the movable contact of the circuit breaker or switch; a support arm secured to the rotary shaft and carrying the ratchet system and around which the toothed wheel is placed; and a pivot fastened to the support arm, being axially offset relative to the rotary shaft and mechanically connected to the spring; wherein the rotary shaft, the cam, the support arm, and the pivot constitute a single part in the form of a crankshaft, the pivot being placed centrally between the cam and the support arm, the pivot being connected to a first end of the spring by a connecting rod, the connecting rod having a first end pivotally connected on the pivot and having a second end connected to the first end of the spring, the rotary shaft being made up of two portions, one of the portions beside the cam and the other portion beside the support arm; and wherein the support arm possesses at least three angularly offset branches with peripheral surfaces supporting the toothed wheel by contacting the tips of teeth of the inner set of teeth, the ratchet system being placed on one of the branches to co-operate with the inner set of teeth of the toothed wheel.

Description

LIST OF FIGURES

(1) The invention and its various technical characteristics can be better understood on reading the following description that is accompanied by four figures, in which, respectively:

(2) FIG. 1 is a perspective view of a large portion of the device of the invention;

(3) FIG. 2 is a face view of a portion of the device of the invention, seen from beside the toothed wheel;

(4) FIG. 3 is a side view of a large portion of the device of the invention; and

(5) FIG. 4 is a side view of the device of the invention shown in full.

DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

(6) FIG. 1 shows a device of the invention without the energy-supply spring and the loading connecting rod that connects the spring to the elements shown in FIG. 1. Among the main elements shown in this figure, there is a toothed wheel 1, having an inner set of teeth 2 and an outer set of teeth 3. The outer set of teeth 3 serves to receive energy for loading the spring, e.g. as delivered by a motor via a toothed gearwheel (not shown) that meshes with the outer set of teeth 3 of the toothed wheel 1. FIG. 1 also shows a cam 4 having a functional outside surface 4A that is used to actuate the movable contact(s) of the electrical installation for engaging or disengaging. The cam 4 is connected via a pivot 5 constituted by a shaft segment to a support arm 6 placed inside the toothed wheel 1. One of the functions of the support arm 6 is to support the wheel. In the embodiment shown in FIG. 1, the support arm 6 is in the form of a star having three branches 6B, but that is merely an example, and embodiments with four branches 6B or even more could also be envisaged. The outside surface 6A of the support arm 6 must be capable of being in contact with the tips of the teeth of the inner set of teeth 2 of the toothed wheel 1.

(7) On either side of the assembly constituted by these four elements, there is the rotary shaft of the device in two portions 7A and 7B. These two portions 7A and 7B are coaxial and they are designed to be supported by bearings. The pivot 5 is offset axially from the rotary shaft 7A, 7B.

(8) It can thus be seen that the rotary shaft 7A, 7B, the cam 4, the pivot 5, and the support arm 6 are constituted and fabricated as a single part. This unit has the general shape of a crankshaft. Naturally, the various elements making up this unit are prevented from moving relative to one another.

(9) Beside the toothed wheel 1, there can be seen an inner rim 1A extending around the entire circumference of the toothed wheel 1. This enables the wheel to be positioned relative to the arm 6 of overall diameter greater than the inside diameter of the lateral rim 1A.

(10) The pivot 5 serves to connect the unit shown in FIG. 1 mechanically to one or more springs for delivering the energy needed for opening or closing the electrical installation. In order to simplify the depiction of the embodiment, no spring is shown in FIG. 1. Nevertheless, the pivot 5 serves to communicate the energy transmitted by the set of elements shown in FIG. 1 to a compression spring via a connecting rod that is likewise not shown.

(11) A pawl 8 pivotally mounted on one end of a branch 6B of the support arm 6 co-operates with the inner set of teeth 2 of the toothed wheel 1 to form a rachet system. The end of the pawl 8 thus penetrates between two teeth of the inner set of teeth 2 of the toothed wheel 1. When the wheel turns clockwise, the pawl 8 is engaged between two teeth of the inner set of teeth 2 of the toothed wheel 1. Under such circumstances, both portions 7A and 7B of the rotary shaft, the support arm 6, and the cam 4 turn by the same amount in the clockwise direction together with the toothed wheel 1.

(12) In contrast, if the support arm 6 turns clockwise, the pawl 8 tends to disengage from the inner set of teeth 2 of the toothed wheel 1. Thus, the assembly secured to the support arm 6 no longer transmits any mechanical moment or energy to the toothed wheel 1.

(13) The presence of a rachet system is needed for loading the spring. This stage of loading the spring is performed by means of an electric motor driving the toothed wheel 1 clockwise by means of an auxiliary wheel (not shown). Still while loading the spring, the pawl thus remains engaged between two teeth of the inner set of teeth 2 of the toothed wheel 1 and all of the elements shown in FIG. 1 turn together clockwise. Thus, the pivot 5 can transmit to the connecting rod the movement that serves to compress the closure spring.

(14) While it is loading the closure spring, when this turning assembly reaches bottom dead-center, i.e. when the connecting rod is in alignment with the closure spring, the spring relaxes. It then drives the pivot 5 and the support shaft in the same direction of rotation as before, but at a very much greater speed. As a result of this acceleration in the rotation of the support arm, the pawl 8 disengages from the teeth of the inner set of teeth 2 of the wheel 1. The wheel 1 is therefore not driven in rotation and does not transmit a jolt to the drive motor.

(15) FIG. 2 shows more clearly the support arm 6 with the rachet device and the toothed wheel 1, which wheel is placed around the support arm.

(16) The rachet system operates as follows. The pawl 8 is mounted to pivot at one end of a branch of the support arm 6, by means of a small pivot pin 9. By means of this pivoting connection, the pawl 8 can occupy two positions. In FIG. 2, the position shown is the position in which the pawl 8 is engaged between two teeth of the inner set of teeth 2 of the toothed wheel 1. In this position, the support arm 6 and the toothed wheel 1 turn together. The second position is the position in which the pawl 8 has been able to pivot about its pivot axis 9 in the counterclockwise direction. In this second position, the pawl 8 is disengaged from the teeth of the inner set 2 of the toothed wheel 1. As a result, the support arm 6 and the toothed wheel 1 can turn separately relative to each other without transferring force or mechanical moments between each other.

(17) FIG. 2 also shows the cam 4 and the inner rim 1A of the toothed wheel 1.

(18) FIG. 3 shows clearly the crankshaft shape of a large portion of the elements of the device that constitutes a single mechanical part, i.e. the two portions 7A and 7B of the rotary shaft, the cam 4, the pivot 5, and the support arm 6.

(19) The pivot 5, which is placed between the cam 4 and the support arm 6, is offset axially relative to the rotary shaft 7A, 7B. It can thus be seen that during a rotation of the rotary shaft 7A and 7B, the position of the pivot 5 relative to an axis perpendicular to the axis of FIG. 3 varies. This position variation corresponds to the variation in the compression of the closure spring.

(20) FIG. 4 reproduces the assembly shown in FIG. 3, i.e., the rotary shaft 7A, 7B, the cam 4, the pivot 5, and the support arm hidden by the toothed wheel 1. A connecting rod 11 is pivotally mounted on the pivot 5 at a first end 11A. It is connected at a second end 11B to a plate 12 having a first end 10A of the closure spring 10 placed thereon, which spring in this type of embodiment is a helical spring. It should be observed that the second end 10B of the spring 10 is stationary.

(21) It can easily be understood that during one rotation of the rotary shaft 7A, 7B, the position of the pivot 5 relative to a plane perpendicular to the plane of FIG. 4 and containing the axis of rotation of the rotary shaft 7A, 7B, varies. Rotation in either direction of the rotary shaft 7A, 7B enables the pivot 5 to rise relative to FIG. 4, thereby compressing the closure spring 10 by raising the plate 12 on which the spring is placed.

Advantages of the Invention

(22) Thus, the control device of the invention proposes combining in a single rigid element the cam 4, the pivot 5, the support arm 6, and its rachet system, together with the rotary shaft 7A, 7B. The various mechanical elements used in prior art devices, such as, for example: a transmission chain between the control system and the spring are avoided. This leads to a much smaller risk of failure and to an assembly that is more compact.